I'm also not trying to generalize to everyone, I'm only surmising that there may be a lot of people like me. It's arrogant to assume your personal experiences apply to specific other people, but it's equally arrogant to assume you're a snowflake and that other people's experience is irrelevant to your situation. Everyone is their own unique blend of the many human commonalities.
In the modern era, there is no question that sleep hygiene is lacking for some, but it isn’t universally sleep hygiene, or universally scheduling, or universally a set amount of hours. It seems that we’re often dealing with different things for different people.
As I briefly mentioned in comment further up, the solution for me was a 9am wake up, and this seems to work consistently and easily with almost any amount of sleep. I can be just fine with 5 hours or 10. It just works. Prior to arriving at a career situation where I could set my own schedule, there were no combinations of solutions which allowed me to wake up at 6am and not be on autopilot and zombified for the first half of the day. And I tried just about every iteration and combination with diligence for years. Luckily I realized early enough in college to just never take classes before 10am or I would have almost certainly struggled.
If we can figure out ways to allow for flex schedules on positions which have no need for timing rigidity, I could easily see our collective productivity rising in measurable ways. And at the very least we won’t be needlessly forcing entire segments of the population to perform at half optimum levels for half of their days.
EX: I have started to get up around 6am even if the room is dark and I am not getting enough sleep. I find it annoying, and nothing changed but my age.